external-dns/source/ambassador_host_test.go
Aleksei Sviridkin 5a55b09f48
feat(annotations): add custom annotation prefix support for split horizon DNS (#5889)
* feat(annotations): add custom annotation prefix support for split horizon DNS

Add --annotation-prefix flag to allow customizing the annotation prefix
used by external-dns. This enables split horizon DNS scenarios where
multiple instances process different sets of annotations from the same
Kubernetes resources.

Changes:
- Add AnnotationPrefix field to Config with validation
- Convert annotation constants to variables that can be reconfigured
- Add SetAnnotationPrefix() function to rebuild annotation keys
- Integrate annotation prefix setting in controller startup
- Update Helm chart with annotationPrefix value
- Add comprehensive split horizon DNS documentation
- Update FAQ with annotation prefix examples

This maintains full backward compatibility - the default prefix remains
"external-dns.alpha.kubernetes.io/".

Co-Authored-By: Claude <noreply@anthropic.com>

* docs(advanced): fix markdown formatting in split-horizon guide

Add blank lines before code blocks to improve markdown rendering
and comply with markdownlint rules.

Co-Authored-By: Claude <noreply@anthropic.com>

* docs(advanced): fix markdown formatting in split-horizon guide

Co-Authored-By: Claude <noreply@anthropic.com>

* docs(charts): regenerate Helm chart documentation

Co-Authored-By: Claude <noreply@anthropic.com>

* test: add AnnotationPrefix field to test configs

Add missing AnnotationPrefix field to minimalConfig and overriddenConfig
test configurations to match the new default value set in NewConfig().

Co-Authored-By: Claude <noreply@anthropic.com>

* test(charts): update error pattern in json-schema test

Update expected error message pattern to match current Helm validation
output format.

Co-Authored-By: Claude <noreply@anthropic.com>

* refactor(annotations): remove init() for explicit initialization

- Remove init() function from annotations package
- Add explicit SetAnnotationPrefix() call in controller/execute.go
- Remove annotation key aliases from source/source.go
- Replace all alias usages with annotations.* references (348 changes in 28 files)
- Add TestMain to existing test files (service_test.go, cloudflare_test.go)

This change makes annotation initialization explicit and predictable,
avoiding hidden global state initialization at import time.

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: update changelog and mkdocs to include annotationPrefix and split horizon DNS

Signed-off-by: Aleksei Sviridkin <f@lex.la>

* docs(split-horizon): fix linting

Signed-off-by: Aleksei Sviridkin <f@lex.la>

* refactor(annotations): replace hardcoded annotation prefix with constant

Replace all hardcoded "external-dns.alpha.kubernetes.io/" strings
with annotations.DefaultAnnotationPrefix constant to establish
a single source of truth.

Changes:
- Add DefaultAnnotationPrefix constant in source/annotations/annotations.go
- Replace hardcoded string in controller/execute.go with constant reference
- Replace hardcoded strings in pkg/apis/externaldns/types.go (2 occurrences)
- Add helm unit tests for annotationPrefix value

This eliminates string duplication and makes future changes easier.

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Signed-off-by: Aleksei Sviridkin <f@lex.la>
Co-authored-by: Claude <noreply@anthropic.com>
2025-11-08 03:56:52 -08:00

698 lines
19 KiB
Go

/*
Copyright 2019 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package source
import (
"context"
"fmt"
"testing"
ambassador "github.com/datawire/ambassador/pkg/api/getambassador.io/v2"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"github.com/stretchr/testify/suite"
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
fakeDynamic "k8s.io/client-go/dynamic/fake"
fakeKube "k8s.io/client-go/kubernetes/fake"
"sigs.k8s.io/external-dns/endpoint"
"sigs.k8s.io/external-dns/source/annotations"
)
const defaultAmbassadorNamespace = "ambassador"
const defaultAmbassadorServiceName = "ambassador"
// This is a compile-time validation that ambassadorHostSource is a Source.
var _ Source = &ambassadorHostSource{}
type AmbassadorSuite struct {
suite.Suite
}
func TestAmbassadorSource(t *testing.T) {
suite.Run(t, new(AmbassadorSuite))
t.Run("Interface", testAmbassadorSourceImplementsSource)
}
// testAmbassadorSourceImplementsSource tests that ambassadorHostSource is a valid Source.
func testAmbassadorSourceImplementsSource(t *testing.T) {
require.Implements(t, (*Source)(nil), new(ambassadorHostSource))
}
func TestAmbassadorHostSource(t *testing.T) {
t.Parallel()
hostAnnotation := fmt.Sprintf("%s/%s", defaultAmbassadorNamespace, defaultAmbassadorServiceName)
for _, ti := range []struct {
title string
annotationFilter string
labelSelector labels.Selector
host ambassador.Host
service v1.Service
expected []*endpoint.Endpoint
}{
{
title: "Simple host",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
},
},
}, {
title: "Service with load balancer hostname",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
Hostname: "dns.google",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeCNAME,
Targets: endpoint.Targets{"dns.google"},
},
},
}, {
title: "Service with external IP",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "service-external-ip",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Spec: v1.ServiceSpec{
ExternalIPs: []string{"2.2.2.2"},
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"2.2.2.2"},
},
},
}, {
title: "Host with target annotation",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
annotations.TargetKey: "3.3.3.3",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"3.3.3.3"},
},
},
}, {
title: "Host with TTL annotation",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
annotations.TtlKey: "180",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
RecordTTL: 180,
},
},
}, {
title: "Host with provider specific annotation",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
annotations.CloudflareProxiedKey: "true",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
ProviderSpecific: endpoint.ProviderSpecific{{
Name: "external-dns.alpha.kubernetes.io/cloudflare-proxied",
Value: "true",
}},
},
},
}, {
title: "Host with missing Ambassador annotation",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{},
}, {
title: "valid matching annotation filter expression",
annotationFilter: "kubernetes.io/ingress.class in (external-ingress)",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "external-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
},
},
}, {
title: "valid non-matching annotation filter expression",
annotationFilter: "kubernetes.io/ingress.class in (external-ingress)",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "internal-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{},
}, {
title: "invalid annotation filter expression",
annotationFilter: "kubernetes.io/ingress.class in (invalid-ingress)",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "external-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{},
}, {
title: "valid non-matching annotation filter label",
annotationFilter: "kubernetes.io/ingress.class=external-ingress",
labelSelector: labels.Everything(),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "internal-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{},
},
{
title: "valid non-matching label filter expression",
labelSelector: labels.SelectorFromSet(labels.Set{"kubernetes.io/ingress.class": "external-ingress"}),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "internal-ingress",
},
Labels: map[string]string{
"kubernetes.io/ingress.class": "internal-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
}},
},
},
},
expected: []*endpoint.Endpoint{},
},
{
title: "valid matching label filter expression for single host",
labelSelector: labels.SelectorFromSet(labels.Set{"kubernetes.io/ingress.class": "external-ingress"}),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
},
Labels: map[string]string{
"kubernetes.io/ingress.class": "external-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
Hostname: "dns.google",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
},
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeCNAME,
Targets: endpoint.Targets{"dns.google"},
},
},
},
{
title: "valid matching label filter expression and matching annotation filter",
annotationFilter: "kubernetes.io/ingress.class in (external-ingress)",
labelSelector: labels.SelectorFromSet(labels.Set{"kubernetes.io/ingress.class": "external-ingress"}),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "external-ingress",
},
Labels: map[string]string{
"kubernetes.io/ingress.class": "external-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
Hostname: "dns.google",
}},
},
},
},
expected: []*endpoint.Endpoint{
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeA,
Targets: endpoint.Targets{"1.1.1.1"},
},
{
DNSName: "www.example.org",
RecordType: endpoint.RecordTypeCNAME,
Targets: endpoint.Targets{"dns.google"},
},
},
},
{
title: "valid non matching label filter expression and valid matching annotation filter",
annotationFilter: "kubernetes.io/ingress.class in (external-ingress)",
labelSelector: labels.SelectorFromSet(labels.Set{"kubernetes.io/ingress.class": "external-ingress"}),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "external-ingress",
},
Labels: map[string]string{
"kubernetes.io/ingress.class": "internal-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
Hostname: "dns.google",
}},
},
},
},
expected: []*endpoint.Endpoint{},
},
{
title: "valid matching label filter expression and non matching annotation filter",
annotationFilter: "kubernetes.io/ingress.class in (external-ingress)",
labelSelector: labels.SelectorFromSet(labels.Set{"kubernetes.io/ingress.class": "external-ingress"}),
host: ambassador.Host{
ObjectMeta: metav1.ObjectMeta{
Name: "basic-host",
Annotations: map[string]string{
ambHostAnnotation: hostAnnotation,
"kubernetes.io/ingress.class": "internal-ingress",
},
Labels: map[string]string{
"kubernetes.io/ingress.class": "external-ingress",
},
},
Spec: &ambassador.HostSpec{
Hostname: "www.example.org",
},
},
service: v1.Service{
ObjectMeta: metav1.ObjectMeta{
Name: defaultAmbassadorServiceName,
},
Status: v1.ServiceStatus{
LoadBalancer: v1.LoadBalancerStatus{
Ingress: []v1.LoadBalancerIngress{{
IP: "1.1.1.1",
Hostname: "dns.google",
}},
},
},
},
expected: []*endpoint.Endpoint{},
},
} {
t.Run(ti.title, func(t *testing.T) {
t.Parallel()
fakeKubernetesClient := fakeKube.NewSimpleClientset()
ambassadorScheme := runtime.NewScheme()
ambassador.AddToScheme(ambassadorScheme)
fakeDynamicClient := fakeDynamic.NewSimpleDynamicClient(ambassadorScheme)
namespace := "default"
// Create Ambassador service
_, err := fakeKubernetesClient.CoreV1().Services(defaultAmbassadorNamespace).Create(context.Background(), &ti.service, metav1.CreateOptions{})
assert.NoError(t, err)
// Create host resource
host, err := createAmbassadorHost(&ti.host)
assert.NoError(t, err)
_, err = fakeDynamicClient.Resource(ambHostGVR).Namespace(namespace).Create(context.Background(), host, metav1.CreateOptions{})
assert.NoError(t, err)
source, err := NewAmbassadorHostSource(context.TODO(), fakeDynamicClient, fakeKubernetesClient, namespace, ti.annotationFilter, ti.labelSelector)
assert.NoError(t, err)
assert.NotNil(t, source)
endpoints, err := source.Endpoints(context.Background())
assert.NoError(t, err)
// Validate returned endpoints against expected endpoints.
validateEndpoints(t, endpoints, ti.expected)
})
}
}
func createAmbassadorHost(host *ambassador.Host) (*unstructured.Unstructured, error) {
obj := &unstructured.Unstructured{}
uc, _ := newUnstructuredConverter()
err := uc.scheme.Convert(host, obj, nil)
return obj, err
}
// TestParseAmbLoadBalancerService tests our parsing of Ambassador service info.
func TestParseAmbLoadBalancerService(t *testing.T) {
vectors := []struct {
input string
ns string
svc string
errstr string
}{
{"svc", "default", "svc", ""},
{"ns/svc", "ns", "svc", ""},
{"svc.ns", "ns", "svc", ""},
{"svc.ns.foo.bar", "ns.foo.bar", "svc", ""},
{"ns/svc/foo/bar", "", "", "invalid external-dns service: ns/svc/foo/bar"},
{"ns/svc/foo.bar", "", "", "invalid external-dns service: ns/svc/foo.bar"},
{"ns.foo/svc/bar", "", "", "invalid external-dns service: ns.foo/svc/bar"},
}
for _, v := range vectors {
ns, svc, err := parseAmbLoadBalancerService(v.input)
errstr := ""
if err != nil {
errstr = err.Error()
}
if v.ns != ns {
t.Errorf("%s: got ns \"%s\", wanted \"%s\"", v.input, ns, v.ns)
}
if v.svc != svc {
t.Errorf("%s: got svc \"%s\", wanted \"%s\"", v.input, svc, v.svc)
}
if v.errstr != errstr {
t.Errorf("%s: got err \"%s\", wanted \"%s\"", v.input, errstr, v.errstr)
}
}
}